1. Field of the Invention
The present invention relates to a refrigerating apparatus with a turbo compressor, and more particularly, to a refrigerating apparatus having an improved structure to efficiently cool a driving motor of a turbo compressor and a bearing member supporting a rotation axis of the driving motor.
2. Description of the Related Art
Generally, a refrigerating apparatus includes a compressor for compressing a gaseous in order to raise the temperature and pressure of the refrigerant; a condenser to condense the gaseous refrigerant compressed in the compressor into a liquid refrigerant; an expansion unit such as a capillary tube or an expansion valve to lower the temperature and pressure of the refrigerant; and an evaporator for absorbing heat from the surrounding air and cooling the surrounding air to evaporate the liquid refrigerant at a low temperature and low pressure received from the expansion unit. Such a refrigerating apparatus is mounted in a refrigerator or an air conditioner and adjusts temperature of a storage portion of the refrigerator or where the air conditioner is disposed.
Hereinbelow, a refrigerator mounted with a turbo compressor will be described as an example.
Generally, the turbo compressor includes a driving motor; a rotating impeller coupled to a rotation axis of the driving motor; a diffuser converting kinetic energy of refrigerant gas discharged by the rotation of the impeller into pressure energy; and a bearing member supporting the rotation axis. While operating, the driving motor and bearing member of the turbo compressor discharge heat at high temperature.
Such a conventional turbo compressor is disclosed in Korean Patent Application No. 1997-64567. The conventional turbo compressor includes a driving motor; a first impeller and a second impeller coupled with the driving motor by a rotation axis and respectively compressing refrigerant gas one after another; a first diffuser and a second diffuser are provided to respectively correspond to the first and second impellers; a motor compartment is provided to accommodate the driving motor; an introducing part provided to introduce a part of the refrigerant gas compressed once by the first impeller and the first diffuser to the motor compartment; and a discharging part is provided to allow the refrigerant gas introduced to the motor compartment to cool down the motor compartment and to be mixed with the refrigerant gas once compressed.
Such introducing and discharging parts are provided between the driving motor and the bearing member supporting the rotation axis of the driving motor and may efficiently cool down the driving motor.
However, the conventional turbo compressor cannot efficiently cool down a plurality of bearing members provided on an outside of the driving motor by the introducing part and the discharging part.
Also, the conventional turbo compressor rotates the impeller with respect to the diffuser, thereby forming a gap between the impeller and the diffuser. As such, the refrigerant gas may leak out through the gap.